I5 750 Overclocking

[novaen]

Hello, i am using an I5 750 clocked to 3.8 ghz but according to core temp it usually just runs at around 2 ghz i'm amusing because it dems ti necessary to not use the full amount but for games would it not be better to have it running at 3.8 all the time?

 

[Lmeow]

If you have SpeedStep on it lowers the CPU clock speed at idle. At 3.8 GHz all the time, it would consume more power, and thus also make your CPU fan louder in order to cool the overclocked CPU.

 

[novaen]

Is SpeedStep in the bios?

If i don;t mind the more power consumption and louder fan then i will get better performance with SpeedStep turned off?

 

[Lmeow]

Well, you won't really get better performance in the sense that it will clock back up to 3.8 GHz when you do use some CPU power, I don't think you'll see much of an improvement if SpeedStep is off (tbh, I'm not even sure if that's what's causing it to clock down to 2 GHz, but just an assumption). If you want to switch it off, you can do so in the BIOS.

 

[iqvl]

In order to turn off speed step, you need to disable C1E, C3/C6/C7 and EIST. However, most peoples will suggest that you leave it on, excluding me though.

 

[novaen]

I'm pretty sure i turned off all those but now it just runs idle at 1.4 and around 2 for playing Bad Company 2 is there anything that requires it to run at full speed?

 

[iqvl]

Hmmmmmmm, a bit odd.

Try disabling the Turbo Boost Technology too.

BTW, what are your core temps?

 

[wolfram23]

Need more info - BIOS settings, voltages, base clock multiplier CPU features etc etc.

Anyway, EIST downlocks the CPU at idle and only at idle, if even one core is being used it will increase to whatever you set it to in the BIOS.

C1E/C States are completely different from EIST. They drop voltages and disable cores at idle. This saves power (idle power for my set up goes from something like 118 watts to 14W).

C States AND EIST are also mandatory if you're using Turbo Boost (which works by disabling unneeded cores (C States) and then boosting multiplier on the active ones (EIST))

IMO you should always keep these features on UNLESS they're causing issues. Save power, lower heat, reduce wear and tear.

Run either Prime95 or Intel Burn Test or some other stability testing software. This will max the CPU usage. Then tell us what it's at (or better yet take a screen shot with CPUZ and HWMonitor active)

1.4 idle = 133x9 which is the stock speeds at idle. "around 2ghz" is a bit vague but at 133bclk that's only 15 or 16 multiplier. Which means it's downclocked. Maybe you set a higher base clock and 15 multiplier, and then accidentally reset the bclk?

You might have CPU throttling occuring due to excessive heat. Are you using a stock CPU cooler??

 

[iqvl]

C1E does have effect on CPU multiplier! Turning off EIST alone won't fix the multiplier.

 

[novaen]

i changed it to 3.2 GHZ and i got this while running Prime 95.

http://img196.imageshack.us/f/coretempd.png/
http://img824.imageshack.us/i/cpuz.png/
http://img256.imageshack.us/i/hardwaremonitor.png/

 

[iqvl]

For that frequency, your core voltage is way too high and so your core temps.
Try 1.20V.

 

[wolfram23]

For that frequency, your core voltage is way too high and so your core temps.
Try 1.20V.

Agreed, I'm using 1.306V at 3.7ghz and with turbo on (4.2ghz) so that voltage is very excessive. novaen, if you're at a speed you're comfortable with you need to start lowering voltages and testing till you get the lowest usable voltage... obviously not a requirement, but it saves power, heat and CPU life (you can probably drop 10C)

 

[novaen]

My Bios settings are:

Intel EIST Disabled
C1E Support Disabled
OC GENE Disable
Memory Ratio 4
QPF Ration 16
Load Line Calibration Disabled
CPU Voltage 1.280
Dram Voltage 1.600
Spread Spectrum Disabled
CPU base frequency 170
CPU Ratio 20

Would these settings suffice or should enable some of them?

 

[iqvl]

CPU voltage is too high! Unless you got an extremely bad chip,it shouldn't require more than 1.20V(with Load Line Calibration enabled) at 3.4GHz.

What is the speed of your RAM(If it is really 170*4, change the Memory Ratio to 6)? What are the specified speed, voltage and timing of your RAM?

In addition, manually set QPI/Vtt/IMC and PCH voltages to 1.14V and 1.05V respectively.

Read through the short and easy guide below if you have no idea on what we are talking about which seems to be the case to me.
http://www.tomshardware.com/forum/256144-29-1156-core-overclocking-guide

 

[cory1234]

Vtt can be raised more than 1.14. The new intel spec sheet states the max vtt is now 1.4v.

You really only need to touch two voltage settings when overclocking these chips, vcore, and vtt.

I had a pretty good chip when I had mine. 1.29vcore, 1.27vtt for 20x200, and for 3.7ghz it was 1.2vcore, 1.21vtt.

For 3.4ghz you can probably just set your vcore to your VID or possibly lower. For 3.7ghz you shouldn't need more than 1.25v, 1.24vtt.

 

[wolfram23]

I would also enable C1E, EIST, and C States. Those are only recommended to be disabled if they're causing trouble, which almost never happens unless you're going for extreme overclocking like over 4ghz. Obviously keeping them off isn't hurting anything... yet... but they're great to have to save power at idle and lower heat.